Thread tension device



Dec. 24, 1940. F. B. JAVERY 2,225,995

THREAD TENSION DEVICE Filed Nov. 1. 1939 Patented Dec. 24, 1940 UNITED STATES THREAD TENSION DEVICE Frank B. Javery, Worcester, Mass., assignorl to Warp Compressing Machine Company, Worcester, Mass., a corporation of Massachusetts Application November 1, 1939, Serial No. 302,347

9 Claims.

The present invention relates to a thread tension device, especially adapted for use on warping machines.

r The principal object of the present invention is a to provide a tensioning device which will exert a slight, but uniform restraining force on a moving thread, and which will, if the pull on the thread isvsuddenly released, prevent overrunning of the thread. In accordance with the present invention, a hollow, non-circular tensioning element is loosely supported above and adjacent to a xed cylindrical abutment, so that with thread passing between the element and the abutment, the element will lie substantially flat on the thread.

Upon sudden breaking of the thread the unbalanced Weight of the element will swing it quickly against the abutment and hold the thread therebetween to prevent overrunning or slackening of the thread. The device is also capable of allow- 2U ing slubs or other imperfections in the thread to pass through without damage to the threads or without affecting the operation of the device.

Other and further objects and advantages of the invention will hereinafter more fully appear,

reference being had to the accompanying drawing, in which:

Fig. 1 is a perspective View of a device embodying the invention.

Fig. 2 is a sectional view through the device.

Fig. 3 is a view similar to Fig. 2, with a thread under tension passing therethrough.

Fig. 4 is a fragmentary view similar to Fig. 3, showing the position of the parts when the thread breaks.

Fig. 5 is a view similar to Fig 4, showing the device passing a slub or imperfection in the thread.

With reference to the drawing, the tensioning device is mounted on a bracket I, being positioned between suitable thread guides 2 and 3 supported by the bracket. The latter has a projecting lug 4 thereon from which projects a cylindrical abutment pin 5, the upper surface of which is substantially in line with the centers of the thread guides 2 and 3, so that thread passing through the guides will rest on the pin without substantial deflection.

Cooperating with the pin is a relatively light sleeve 6 which is substantially elliptical or oval in cross section, and this sleeve is supported loosely on a small diameter pin l positioned above and forwardly of the pin 5. The axis of the second pin is approximately in a vertical plane tangential to the periphery of the pin 5. It will be noted that the small pin 'l is spaced from the lower and larger pin 5 a distance considerablyy greater than the wall thickness of the sleeve 6, this distance being great enough to allow the passage of a thread 8 therebetween and also such slubs or imperfections in the thread as are unobjectionable. However, this spacing is so controlled that any large imperfections in thethread which might prove to be undesirable will be wedged between the sleeve and the pin 5 to stop the passage of the thread. 10

The thread is drawn between the guides 2 and 3 in the direction indicated by the arrow, Fig. 3, and the pull on the thread tends to move the sleeve 6 into the substantially horizontal position, with the inside of the sleeve providing a substan- ,15 tially constant drag or tension on the thread. It will be noted that in the normalA position of the sleeve the thread runs slightly out of a straight line as it passes through the device, being bent downwardly by the slight weight of the sleeve, 20 thus assuring a Contact between the sleeve and thread for a substantial distance. If vfor any reason the pull on the thread is released, as for example, by stopping of the warping machine to which the device is'attached, the sleeve is no 25 longer maintained in its horizontal position by the tension on the thread and immediately swings downwardly by its own weight to the position of Fig. 4, clamping the thread against the larger pin 5 and preventing movement of the thread in 30 either direction. Such swinging movement is not entirely a pivotal movement about the small pin l, but is partly a pivotal movement about this pin and partly merely a downward swinging movement of the sleeve, since, when the thread is 35 under tension, the sleeve is not drawn tightly against the pin, but tends to float with only a slight guiding contact with the pin 1.

As shown in Fig. 5, if an imperfection such as a small slub 8a occurs in the thread, the sleeve 6 40 will move slightly away from the pin 5, this movement being permitted by the free support of the sleeve on the small pin 1 to provide space enough between the pin 5 and the sleeve for the slub to pass therebetween. It will be apparent that if 45 the slub is so large as to be objectionable, the space between the sleeve and pin 5 will not allow its passage.

I claim:

1. In a thread tensioning device, a iixed abut- 50 ment over which a thread is guided, and a noncircular element eccentrically pivoted above said abutment and forwardly thereof in the direction of thread travel, said non-circular element having its axis substantially at right angles to the 55 direction of thread travel, with the thread passing between said element and abutment, said element resting against the xed abutment when a thread is not under tension, and rocking upwardly when the thread is placed under tension, so that the thread has a substantially straight passage past the abutment and element.

2. In a thread tensioning device, a fixed abutment over which a thread is guided, a non-circu lar sleeve and a pin adjacent to the abutment on which the sleeve is loosely mounted, with the thread to be tensioned passing between said sleeve and abutment, said pin supporting the sleeve in a position for engagement normally withl the abutment, and in a position to move upwardly with respect to the pin when the thread is placed under tension.

3. In a thread tensioning device, a fixed abutment over which a thread is guided, a non-circular sleeve and a pin above and forwardly of the abutment in the direction of thread travel, the sleeve being loosely mounted on said pin, said pin supporting the sleeve in a position for engagement normally with the abutment, and in a position to move upwardly with respect to the pin when the thread is placed under tension.

4. In a thread tensioning device, an elliptical sleeve pivoted on an axis adjacent one end of the ellipse, and an abutment against which the sleeve rests, with the thread to be tensioned passing between the sleeve and said abutment, said sleeve being positioned above the abutment for the thread to pass thereunder, said sleeve rocking upwardly as the thread is placed under tension.

5. In a thread tensioning device, an elliptical element pivoted on an axis adjacent one end of the ellipse, and a pin against which the element rests, the thread to be tensioned passing between the element and pin, the spacing of the pin and element being greater than the thickness of a thread to be tensioned to allow passage of small thread imperfections between the element and the pin.

6. In a thread tensioning device, a substantially horizontal pin over which a thread is guided, and an elliptical element pivoted above said pin and forwardly thereof in the direction of thread travel, the thread passing between said element and pin, said sleeve and pin being spaced a greater distance than the thickness of a thread to be tensioned to allow passage of small thread imperfections between said sleeve and pin.

7. In a thread tensioning device, a base, a horizontal pin mounted thereon, a small pin above said horizontal pin and forwardly thereof in the direction of thread travel, an elliptical sleeve pvotally mounted on said small pin, land thread guides directing thread over the main pin and substantially tangential thereto, the thread passing between said main pin and sleeve, said sleeve normally hanging from the small pin and resting against the main pin, said sleeve when the thread is under tension assuming a substantially horizontal position to allow the thread to pass through the device Without substantial deflection.

8. In a thread tensioning device, a base, a horizontal pin mounted thereon, a small pin above said horizontal pin and forwardly thereof in the direction of thread travel, an elliptical sleeve pivotally mounted on said small pin, and thread guides directing thread over the main pin and substantially tangential thereto, the thread passing between said main pin and sleeve, said small pin being so positioned that the sleeve normally rests against the main pin, and said sleeve being rocked upwardly when the thread is placed under tension to allow the thread to pass through the device without substantial deflection, the spacing of the pins providing for the elliptical sleeve to rest in a substantially horizontal position on a thread passing through the device` when the thread is under tension, the elliptical sleeve lying against the main pin with its longitudinal axis substantially vertical when the thread tension is relieved.

9. In a thread tensioning device, a base, a horizontal pin mounted thereon, a small pin above said horizontal pin and forwardly thereof in the direction of thread travel, an elliptical sleeve loosely mounted on said small pin, and thread guides directing thread over the main pin and substantially tangential thereto, the thread passing between said main pin and sleeve.

FRANK B. JAVERY. 

